NEUROENDOCRINE CELL HYPERPLASIA IN COLONIC TISSUE USED FOR LUNG TERM AUGMENTATION CYSTOPLASTY

A case is described of neuroendocrine cell hyperplasia in intravesical colonic mucosa, implanted previously during augmentation cystoplasty. The patient was a 28 year old man born with posterior urethral valves , a non-functioning right kidney, and a poorly functioning dilated lef t kidney. The hyperplasia consisted of pure neuroendocrine acini and t ubules within the lamina propria, separate from the normal intestinal glands. Adjacent intraepithelial colonic neuroendocrine cells were inc reased diffusely. Rectal biopsy and previous biopsies of intravesical colonic tissue contained normal neuroendocrine cell populations. Impla ntation of gut segments into the urinary tract predisposes to late neo plasia, but there is only one report of carcinoid tumour in uroenteric tissue. Intestinal neuroendocrine cell hyperplasia usually occurs dif fusely rather than as aggregates, except when associated with adjacent carcinoid tumour. Both diffuse and nodular hyperplasia were present i n this case, with an unusual and striking morphology. This is the firs t report of neuroendocrine cell hyperplasia in gastrointestinal tissue implanted into the urinary tract; this raises the possibility of a ri sk of late carcinoid tumour in uroenteric segments.